KMT2C and breast cancer: Additionally, mutations in TP53, CDH1, NCOR1, PTEN and NF1, CCND1 amplification, as well as loss of TP53 and KMT2C were associated (FDR q-value <0.1, permutation test) with ‘APOBEC high’ samples in different breast cancer subtypes (Fig. 1c), which could explain the heterogeneity in APOBEC3 enrichment among samples within subtypes.